1. Field of the Invention
The field of this invention is nucleic acid vectors.
2. Background of the Invention
The introduction of an exogenous nucleic acid sequence (e.g. DNA) into a cell, a process known as xe2x80x9ctransformation,xe2x80x9d plays a major role in a variety of biotechnology and related applications, including research, synthetic and therapeutic applications. Research applications in which transformation plays a critical role include the production of transgenic cells and animals. Synthetic applications in which transformation plays a critical role include the production of peptides and proteins. Therapeutic applications in which transformation plays a key role include gene therapy applications. Because of the prevalent role transformation plays in the above and other applications, a variety of different transformation protocols have been developed.
In many transformation applications, it is desirable to introduce the exogenous DNA in a manner such that it is incorporated into a target cell""s genome. One means of providing for genome integration is to employ a vector that is capable of homologous recombination. Techniques that rely on homologous recombination can be disadvantageous in that the necessary homologies may not always exist; the recombination events may be slow, etc. As such, homologous recombination based protocols are not entirely satisfactory.
Accordingly, alternative viral based transformation protocols have been developed, in which a viral vector is employed to introduce exogenous DNA into a cell and then subsequently integrate the introduced DNA into the target cell""s genome. Viral based vectors finding use include retroviral vectors, e.g. Maloney murine leukemia viral based vectors. Other viral based vectors that find use include adenovirus derived vectors, HSV derived vectors, sindbis derived vectors, etc. While viral vectors provide for a number of advantages, their use is not optimal in many situations. Disadvantages associated with viral based vectors including immunogenicity, viral based complications, and the like.
Accordingly, there is continued interest in the development of additional vectors for use in transformation protocols. Of particular interest is the development of non-viral vectors that provide for stable integration of exogenous DNA in a cell genome through a mechanism other than homologous recombination.
Relevant Literature
U.S. patents of interest include: U.S. Pat. Nos. 5,719,055 and 4,670,388. Other references of interest include: Rio et al., xe2x80x9cIdentification and Immunochemical Analysis of Biologically Active Drosophila P Element Transposase,xe2x80x9d Cell (Jan. 17, 1986) 44:21-32; and Rio et al., xe2x80x9cEvidence for Drosophila P Element Transposase Activity in Mammalian Cells and Yeast,xe2x80x9d J. Mol. Biol. (1988) 200: 411-415.
Additional articles of interest include: Schouten et al., Nuc. Acids Res. (1998) 26:3013-3017; Ivics et al., Cell (1997) 91: 501-510; Luo et al., Proc. Nat""l Acad. Sci USA (1998) 95:10769-10773; and Ivics et al., Proc. Nat""l Acad. Sci. USA (1996) 93:5008-5013.
P element derived vectors and methods for their use in the insertion of an exogenous nucleic acid into a target cell genome are provided. The vectors of the subject invention include a pair of P element transposase recognized insertion sequences, e.g. P element derived 31 base pair inverted repeats, flanking at least two transcriptionally active genes. In practicing the subject methods, a vector as described above carrying an exogenous nucleic acid is introduced into a target cell under conditions sufficient for transposition of the exogenous nucleic acid from the vector into the target cell genome. The subject methods find use in a variety of transformation applications, including research, polypeptide synthesis and therapeutic applications.